This is my first year with a bearing Granny Smith tree. The apples want be ripe for sometime. I was surprised the new little apples start out red. Australia is the originators of a lot of good apple varieties as you know.

1. How are Chill Hours calculated? My system has been up about 2 weeks on Wunderground, and today.ini shows 7.3481 chill hours. I'm sure it is incorrect, we have not dropped below 45 degrees yet here in Texas. Second, we have had a high above 80 since I have started the system, chill hours should have been removed from the count.

2. Is there a way to display chill hours from the system in Wunderground web page, or on the Cumulus screen on my PC? Is the only way to get the value to read the today file directly or to place the tag in HTML?

It checks the temperature once a minute, and if it's below the threshold, it adds a minute to the Chill Hours total.

Quote:

My system has been up about 2 weeks on Wunderground, and today.ini shows 7.3481 chill hours. I'm sure it is incorrect, we have not dropped below 45 degrees yet here in Texas.

I'm reasonably sure the code is correct, no-one else seems to have an issue. Perhaps your station is giving false readings - Fine Offset stations commonly do. I'd need to see all of your data files, and the ChillHourThreshold setting from cumulus.ini.

Quote:

Second, we have had a high above 80 since I have started the system, chill hours should have been removed from the count.

Sorry, I don't understand, could you please explain? The Chill Hours figure has nothing to do with high temperatures, it just counts the period when the temperature was below a pre-set figure.

Quote:

Is there a way to display chill hours from the system in Wunderground web page

No, Wunderground has it's own fixed set of data and you can't change it.

Quote:

or on the Cumulus screen on my PC?

You can view the total on the 'This Year' summary screen.

_________________SteveSanday Weather----------------------------------------------------------------------------------------------------------------------------------Like Cumulus and want to support it? Please donate!

Thank you for the information. I don't suppose you can tell me the value? We measure chill hours as time between 45 and 32 degrees F, and if chill hours start accumulating and then the temp goes back ABOVE 60 degrees F, chill hours are subtracted. I'll assume the formula for Cumulus is not that complex?

And thanks for pointing out where to find them.....thought I looked at every screen....

Thank you for the information. I don't suppose you can tell me the value?

The default threshold is 7C or 45F. All time spent below this threshold contributes to the total, calculated once a minute.

Quote:

We measure chill hours as time between 45 and 32 degrees F, and if chill hours start accumulating and then the temp goes back ABOVE 60 degrees F, chill hours are subtracted. I'll assume the formula for Cumulus is not that complex?

I added the chill hour facility by request and implemented it as best as I could with the information I had. According to this page on Wikipedia - http://en.wikipedia.org/wiki/Chilling_requirement - only the 'Utah' model has the 'negative' effect that you describe; I have not implemented this, just the 'simplest' model.

_________________SteveSanday Weather----------------------------------------------------------------------------------------------------------------------------------Like Cumulus and want to support it? Please donate!

Thank you for the information. I don't suppose you can tell me the value? We measure chill hours as time between 45 and 32 degrees F, and if chill hours start accumulating and then the temp goes back ABOVE 60 degrees F, chill hours are subtracted. I'll assume the formula for Cumulus is not that complex?

And thanks for pointing out where to find them.....thought I looked at every screen....

jferristx, there are many, ways to calculate chill hours. The most widely accepted chill hour model is the simple, everything below 45F. This has been the model for many, many years. After doing quite a bit of research, the chill hours value given to fruit bearing trees, is often overstated and the majority of chill hour values is based on this model. The chill hour value for trees is more of a rule of thumb than a specific value.

The chill hour model you mentioned is one that is accepted in specific geographic areas but becomes inaccurate outside of these areas. Check with your local agriculture extension agent to find the model best suited for your area.

Since Cumulus is used world wide, the simple model works best for the largest number of users.

Many thanks for the explanation. The Utah model "might" be of issue where I live. It is not unusual to have 40-50 degree temp swings during a week. I save my data, next spring I'll run it against the other model and see if it makes much if any difference.

Who is online

Users browsing this forum: No registered users and 0 guests

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum